I bought a used 2008 YZ250 from a dealer here locally. When i bought the bike i started it rode it the whole 9 yards and everything was fine. so i loaded the bike up and got it home and decided to take it up the street just becasue i couldn't control myself . i got back to my house and stopped and gas started pouring out of the overflow line from the carb. I was thinking the same thing u are its probably a stuck float or the level needs adjusted so i pulled the carb and messed with it for a good hour and a half and got it to were it wasn't over filling so i put it back on the bike. i decided to start the bike for a min to make sure and what do u know after shutting down gas came pouring out again. i decided to call the dealer and to make a long story short sense it was used and i did buy the extended warranty they said i would have to pay for them to even look at it. This is were i need help i pulled the carb back off i checked to see if the float well floated and it did. then i checked to make sure the needle that sits on the float sealed correct and it seals fine (both off and on the float) and it doesn't appear to be damaged. i can adjust the carb to were it doesn't leak when the carb is out of the bike and just hooked to the gas tank but as soon as i start the bike once the carb is back in it starts to over fill again. i have run out of ideas. i need help!!!